The Clinch River (CR) and North Fork Holston River (NFHR) contain some of the most diverse freshwater mussel assemblages in the United States; however, both rivers are experiencing declines in mussel populations. The first component of this study used histological evaluations and water quality data to determine whether mussels were negatively impacted in the CR zone of decline (ZD) and to inform future management of freshwater mussels in the river. In the 91 kilometer (km) section from Carbo, Virginia (CRKM 431) downstream to Speers Ferry, Virginia (CRKM 340), referred to as the ZD, mussel density decreased >90% from 1979 to 2014 at key sites such as Semones Island (CRKM 378.3) and Pendleton Island (CRKM 364.2). Laboratory propagated mussels were placed in cages in the river for one year from June 2012 to May 2013 at four sites within the ZD and four sites in reaches where mussel populations remain stable or are increasing, a zone of stability (ZS). The survival, growth and histological results indicated that there are continuing impacts to mussels in the ZD. Research investigating impacts to the ZD and methods to improve water quality in this zone are needed. The laboratory component of this study examined sublethal effects of potassium (K⁺), chloride (Cl⁻), and un-ionized ammonia (NH₃-N) on mussel tissues at concentrations relevant to those found in the NFHR. Historical industrial activities at Saltville, Virginia, as well as continued pollution of the NFHR from chemical waste ponds at this location, are believed to be significant contributors to mussel declines. Contaminant seepages from the waste ponds that include Cl⁻, K⁺, and NH₃-N have been shown to be toxic to adult and juvenile mussels. A three-month laboratory study was conducted to assess impacts to organ tissues (gills, digestive glands, kidneys, and gonads) of adult Villosa iris exposed to environmentally relevant concentrations of K⁻ (4 and 8 mg/L), Cl⁻ (230 and 705 mg/L), and NH₃-N (0.014 and 0.15 mg/L) using histological evaluations. No detectable differences were observed among the histological endpoints from mussels held in treatments and control (p>0.05). The study design was modified and repeated using increased concentrations of K⁺ (8, 16, and 32 mg/L) and Cl⁻ (705, 1410, and 2820 mg/L) for a two-month exposure period. Due to issues with maintaining NH3-N in mussel holding chambers, the second study did not the second study did not include NH₃-N exposures. Control mussels in both studies had a higher abundance of lipofuscin in kidneys and degraded cytoplasm in the digestive gland diverticula compared to baseline mussels, indicating that captivity influenced mussel tissues. Future studies are needed to more thoroughly address these captivity effects. Both survival and histological data in the second test showed a significant negative effect of the increased concentrations of Cl⁻ and K⁻, which were representative of those found at some sites in the NFHR downstream of Saltville, Virginia. / Master of Science

Freshwater mussel propagation techniques were tested at the Virginia Department of Game and Inland Fisheries Aquatic Wildlife Conservation Center through a series of three experiments. Experiment 1 tested the suitability of a pond and raceway for rearing juvenile oystermussels (Epioblasma capsaeformis) and wavyrayed lampmussel (Lampsilis fasciola). This experiment was prematurely terminated due to predation on mussels by fathead minnows (Pimephales promelas). Experiment 2 evaluated growth and survival of juvenile rainbow mussels in outdoor troughs and indoor aquaria. There was no significant difference in survival or growth between the two systems. Experiment 3 used troughs similar to those in Experiment 2 to rear E. capsaeformis and L. fasciola under two silt regimes. Survival for Experiment 3 was significantly greater for L. fasciola. The comparison between silt regimes indicated that individuals in the high-silt treatment had better survival than those in the low-silt treatment. The difference between these 2 treatments may be a reflection of increased escapement in the low-silt treatment, which may have resulted from more frequent disturbance during sampling. Growth of L. fasciola was significantly greater than E. capsaeformis, and was greater in the low-silt treatment. A habitat survey of the Clinch River, Virginia was conducted from Blackford, Clinch River Kilometer (CRK) 478 to the Tennessee border, CRK 325. Physical characteristics identified in the survey were combined with water quality and impact source data to develop a habitat suitability index for freshwater mussels within this study reach. Model parameters were indexed and weighted to give a final suitability ranking. Habitat units having the highest overall ranking included: Nash Ford (CRK 449), Artrip (CRK 442), several riffles and runs below Carterton (CRK 417), upstream of Mill Island (CRK 389.5), and Pendleton Island (CRK 365), and Speers Ferry (CRK 333-325). Potential locations for habitat restoration projects and additional monitoring were also identified. / Master of Science

American Electric Power's (AEP) coal-fired Clinch River Plant, a power-generating facility in Carbo, Russell County, Virginia (USA), has impaired Clinch River biota through toxic spills in 1967 and 1970, and effluent copper (Cu) concentrations that were reported to have exceeded water quality criteria from 1985-1989. These impacts have provided impetus for many research projects addressing the absence of bivalves, including federally protected species of native mussels (Unionoidea), from sites influenced by CRP effluent. Modifications in CRP effluent during 1987 and 1993 drastically reduced Cu levels and warranted the present study, which assessed long-term biological recovery in Clinch River biota near the CRP. In 2000-2001, surveys of benthic macroinvertebrate communities and instantaneous measures of effluent toxicity did not foretell significant reductions in survivorship and growth of field-caged Asian clams (Corbicula fluminea) at sites downstream of the CRP. More importantly, these results indicated renewed toxicity in CRP effluent. Additional transplant studies using two enclosure types were conducted to isolate effects attributable to CRP effluent from the potentially confounding effects of substrate variability among study sites. While it was found that mean growth of clams was greatest in the enclosure that minimized substrate variability (p=0.0157), both enclosure types clearly distinguished significant impairment of survivorship and growth at sites downstream of the CRP discharge, and strengthened the association between impairment and CRP effluent. An intensive field investigation was undertaken to determine whether impairment observed in transplant studies extended to resident bivalves. During 2001-2002, densities and age structures of C. fluminea and distributions of mussels suggested that impairment indeed extended to resident bivalves for a distance of 0.5 to 0.6 km downstream of the CRP discharge. Impairment of bivalves was less evident below (1) a fly ash landfill and (2) coal mining activities and low-volume leachate from a bottom ash settling pond. With respect to long-term recovery, modifications in CRP effluent treatment have reduced Cu concentrations from an average of 436 mg/L in 1985-1989 to 13 mg/L in 1991-2002. Subsequently, Cu body burdens of Asian clams (Corbicula fluminea) transplanted within CRP influence have decreased from 442% of levels accumulated at reference sites in 1986, to 163% of these levels in 2002. The reduction in effluent Cu largely explains recovery of most benthic macroinvertebrate community parameters (e.g., richness, diversity) at influenced sites from levels that were typically less than 70% of reference levels, to levels that frequently range from 80 to greater than 100% of reference levels. Nevertheless, bivalves remain impaired downstream of the CRP; survivorship and growth of C. fluminea transplanted to CRP-influenced sites have typically been less than 40 and 20% of reference values, respectively. Furthermore, C. fluminea has seldom been encountered within CRP influence for nearly two decades. Likewise, native mussels remain absent within CRP influence, but recent surveys suggest their downstream distributions are more proximate to the CRP discharge than has been reported previously. A preliminary assessment of factors potentially contributing to toxicity revealed that (1) water reclaimed from settling basins for discharge with CRP effluent significantly impaired fecundity of ceriodaphnids at concentrations of 50%, (2) LC50 values for industrial treatment chemicals were misrepresented on Material Safety Data Sheets and consequently, were subject to misapplication by operators, (3) Cu concentrations of 96 mg/L significantly impaired growth of Asian clams in artificial stream testing, and (4) effluent Al exceeded acute and chronic water quality criteria, suggesting this ion should receive further consideration in future studies. / Master of Science

The rate of extinction of plant and animal species has accelerated at an alarming rate throughout the 20th century. This depletion has resulted in greater legislative control over wildlife within the United States, and the eventual passage, in 1973, of the Endangered Species Act (ESA). The ESA establishes regulations designed to protect species which are threatened with extinction. The ESA has evolved out of past legal statutes and jurisprudence concerning the management and protection of wildlife, but the ESA has created controversy since inception. The latest criticisms concern its lack of success in meeting stated policy goals of preserving species richness and recovering listed species. As a result, a new movement has developed which seeks to change the traditional species-by-species approach of the ESA to an approach which concentrates on entire ecosystems. Ecosystem approach proponents sight various advantages, one of which is cost-effectiveness. This thesis analyzes the development of wildlife protection within the United States, and the Endangered Species Act in particular. The purpose of this analysis is to examine both the legislative powers granted for wildlife protection, and the feasibility of the ESA to encompass ecosystem protection. Modifications to the ESA are proposed. The Clinch River Valley, in Southwest Virginia and Northeast Tennessee, is used as a case study for a cost-effectiveness analysis of an ecosystem approach and species-by-species approach. Costs generated through Fish and Wildlife Service recovery plans are used in conjunction with generated ecosystem plan recovery costs. The results of the cost-effectiveness analysis show that an ecosystem approach is more cost-effective in meeting the recovery goals within the 0inch River Valley. The ESA can be modified to incorporate an ecosystem approach. Such modification can protect species richness and allow for a priority ranking system for protection. / M.S.

Basin-wide visual estimation techniques developed in the Pacific Northwest for small streams were modified to survey about 180 river kilometers (rkm) of the North Fork Holston River and about 16 rkm of lower Little River (Clinch River tributary) in southwestern Virginia during the summer of 1992 and 1993, respectively. Presence-absence models were developed, using stepwise logistic regressions, from habitat characteristics measured on a scale ranging from large-scale (geographic location) to local-scale (habitat-unit characteristics) for blotchside logperch (<i>Percina burtoni</i>) and tangerine darter (<i>P. aurantiaca</i>) in the North Fork Holston River. Transferability of models, developed for both species in the North Fork Holston River, to Little River were tested by comparing the models' predictions with the data collected during the Little River survey. / Master of Science

A freshwater mussel survey was conducted in Indian Creek, Tazewell County, Virginia, during 1996 and 1997. Fifteen species were identified, including the federally endangered <i>Epioblasma florentina walkeri<i>, <i>Villosa perpurpurea</i>, and <i>Quadrula cylindrica strigillata</i>. Population assessments and fish host identifications were completed for the tan riffleshell and purple bean populations. Host fish for <i>E. f. walkeri</i> were limited to the banded and mottled sculpin, greenside darter, redline darter, fantail darter, and snubnose darter. Fish hosts identified for <i>V. perpurpurea</i> also were the banded and mottled sculpin, greenside darter, and redline darter. Size class structure of the tan riffleshell population ranged from 19.9 to 53.3 mm, with the population estimated at nearly 700 individuals with a density of 0.015/m². Size class structure of the purple bean population ranged from 22.9 to 66.7 mm, with the population estimated at only 70 individuals with a density of 0.002/m². Host fish also were identified for <i>Dromus dromas</i> and <i>Lemiox rimosus</i>. The fantail darter was identified as a host for <i>D. dromas</i>, with the snubnose darter serving as a host for <i>L. rimosus</i>. Additional percids were implicated as hosts for both mussel species. A molecular genetic key for identifying host fishes of the upper Clinch River also was constructed. The key was constructed through the analysis of restriction fragment length polymorphisms from amplified regions of mussel DNA. Thirty-six unionid species were incorporated into the key. No host fishes were identified due to an unsolved problem with amplifying DNA from glochidia collected from wild fish. / Master of Science